The invention described herein relates to a process for refining foodstuffs, and to plant therefor.
Refining of foodstuffs is widespread in the food industry; fruit and vegetable produce provide a typical example, and meat processing is likewise a case in point. The refining process reduces such produce and products to juice, pulp, puree, paste etc. . . .
The machinery normally employed in refining processes of the type consists of a casing that accommodates a screen in the form of a grille or sieve, generally cylindrical or conical in shape, inside of which a shaft with vanes is made to rotate. The foodstuff is fed into the screen, and forced through to the outside by rotation of the vanes.
The product issuing from the screen, which most commonly will be the juice and the pulp of whatever produce is fed in, is collected and conveyed forward either to successive processing stages or to bottling or packaging stations, whereas waste matter such as the seeds and the peel of fruit, vegetables, or other market garden produce, are drawn off from the inside of the screen, usually by a continuous method.
A given granulometry selected for the end-product in process, fine or coarse as this may be, is obtained by using a number of machine stages arranged in series, each stage of which consists of a machine identical to the preceding machine, though with a screen having holes of smaller diameter, thereby decreasing in size stage by stage. Such machines are known to a person skilled in the art under a variety of names--viz, strainers, refiners, super-refiners, disintegrating mills of the hammer or colloid type, cutters etc., depending upon the granulometry they are capable of producing.
The end-products obtained by this method are generally used in the manufacture of fruit juice beverages, baby foods, preserves of various kinds, and where meat processing is concerned, in the preparation of pastes ultimately to be packed as sausage meat (wurst, mortadella . . .)
The processing methods in question subject foodstuffs to a mixing and beating action of energetic and prolonged nature, as a result of which a considerable quantity of air is entrained; this heightens the degenerative effects of oxidation on all the chemical constituents of the foodstuff. The general upshot is a deterioration of the organoleptic and nutritional properties of the end-product, and of its appearance--viz, the effects on color and vitamin content, the oxidation of fatty substances and the denaturation of amino acids and proteins, to name only the most notable of such adverse factors.
The main object of the invention described herein is that of overcoming the abovementioned drawbacks by providing a process and relative plant that will permit of achieving a marked improvement in the quality, as well as in the general properties, of food products manufactured by way of a process of the type in question.